Smart supplies, components and capital equipment

ABSTRACT

The present invention relates to capital equipment units, such as systems for providing medical treatment, that are associated with smart supplies. The smart supplies are tagged with data carriers which may encode such information as a unique ID for the supply or component, the identification of the supply or component, the identification of the source of the supply or component, the status of whether said supply or component has been previously used, the expiration date of the supply or component, and in the case where the supply or component contains drug, the purity levels of the drug and the concentration levels of the drug. The capital equipment units or their users then utilize the information to assure quality of any procedure run with the units, by way of improved pre-use checks, certification of the supplies for use, record keeping, inventory control, and charge capture.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of co-pending U.S. patent applicationSer. No. 10/151,255, filed May 21, 2002 now U.S. Pat. No. 7,299,981,which claims priority to U.S. Provisional Patent Application No.60/291,943 filed May 21, 2001 all of which are incorporated herein byreference in their entirety.

FIELD OF THE INVENTION

The present invention relates to product authentication by way ofidentification and certification of the origin or manufacturer ofmedical supplies, components, and other devices. Such authenticationensures, among other things, proper fit and operation via qualityassurance of appropriate purity, concentration, sterility, calibrationand manufacturing tolerance of the devices. The present invention alsorelates to marking a single patient use medical supply or component asused, once it has been used, in order to prevent cross-contaminationwith infectious disease between patients.

BACKGROUND OF THE INVENTION

Many medical procedures, such as the administration of drugs (e.g.,sedative and analgesic drugs) are safety-critical tasks with patienthealth at issue. Therefore, identification and certification of theorigin and manufacturer of medical supplies and the identification ofdrugs to be administered to a patient is important. Such identificationand certification enhances patient safety by ensuring and enhancing thequality of pharmaceuticals and single-patient use disposable devices,including assuring such criteria as proper purity, concentration,sterility, calibration, and manufacturing tolerance.

Also important are means for preventing medical supplies having alreadybeen used with one patient from being subsequently reused with anotherpatient. Cross-contamination between patients is a concern because ofinfectious diseases caused by blood-borne pathogens such as the HumanImmunodeficiency Virus (HIV) and hepatitis B and C, and by respiratorypathogens such as multi-drug resistant tuberculosis. Further,contamination of certain pharmaceuticals have caused fatal cases ofsepticemia because these compounds support the growth of bacteria.

In an attempt to prevent cross-contamination, medical equipment,components and supplies are often sterilized prior to reuse with adifferent patient. However, recent studies indicate that sterilizationof many medical devices, especially those that have valves, complexmechanisms, or narrow and long lumens (e.g., laparoscopic trocars,endoscopic biopsy forceps, and fiberscopes), may not be entirelyeffective.

An alternative way to avoid cross-contamination is through singlepatient use (disposable) medical supplies and components. Disposablemedical supplies and components will not prevent cross-contamination ifthey are reused. Therefore, concerns remain as to both the deliberateand the unintentional reuse of disposable medical supplies andcomponents. There is also concern beyond patient cross-contaminationwith the unauthorized sterilization and/or reuse of disposable medicalsupplies and components which are not designed or validated to besterilized or to have a long service life.

Goods that outwardly and superficially look like a component or supplyof a medical device having the appropriate form, fit, and function to beused with the device may actually be uncertified products that wereotherwise not manufactured according to original design specifications.In many circumstances where quality and reliability of performance aremission-critical, the customer or other user may not be able to discernthe difference between uncertified and genuine parts. For example,proper use of a drug administration or infusion system requiresknowledge of the drug concentration, dead space volume in the infusiontubing and drug pump cassette, and calibrated tubing and compressionsurfaces (in order to generate volumetric control of the rate of druginfusion). This information may not be known or be outside thespecifications for uncertified versions of components or supplies ofinfusion systems.

If medical supplies were “smart,” the detection of the presence orabsence of certified medical supplies and their use-condition could beeasily automated. Automation may also relieve the clinician of the choreand memory load of certifying products and may enhance patient safety byensuring that all necessary supplies are present and where appropriate,unused, before the initiation of a medical procedure.

Further, despite the best quality assurance efforts of manufacturers,contaminated or defective products sometimes reach the marketplace.Ensuing product recalls are an extremely costly endeavor for themanufacturer. An identification system that would facilitatelocalization and removal of every single recalled product would beadvantageous. As an added safety measure, it would be beneficial if thebatch number and unique identification numbers of the recalled productscould be programmed into the associated delivery device, like aconscious sedation machine, or at any dispensing location like apharmacy or a centralized database so that any recalled product, such asa tainted drug vial, slipping through the recall is rejected by thedelivery device.

SUMMARY OF THE INVENTION

The present invention provides apparatuses and methods for permittingmedical supplies and components to interact with medical capitalequipment units (e.g., medical treatment systems such as, among others,sedation and analgesia delivery systems, anesthesia machines andworkstations, x-ray machines, dialysis machines) and clinicalinformation systems for the purpose of improving patient safety whileenhancing the efficiency of the clinical process flow.

The present invention provides a system for ensuring the safe andefficient use of devices with tamper-evident seals by way of reportingto their users whether the tamper-evident seals are intact and whetherinspection or replacement of the devices having the seals is past due.Also, regarding the use of packaged pre-assembled kits that include allthe supplies and components required for a particular procedure, medicalor otherwise, or individual medical devices, the present inventionprovides a system which promotes and monitors the unpackaging of suchkits and devices just prior to use. Such promotion and monitoringensures sterility of the kits and individual devices prior to their usewith a patient.

Regarding pre-use check sequences for the operation of some medicalsystems, such as sedation and analgesia administration devices, thepresent invention provides a system that detects the presence or absenceand the use-condition of medical supplies and components required forthe operation of the systems. Thus the invention may enhance patientsafety by making sure that necessary supplies and components (regularand emergency) are present and functional and where appropriate, unused,before the operation or procedure of the medical systems begins.

One system according to the present invention can track individual drugcontainers, identify how much drug is used or even wasted, and can thusmonitor the efficacy of re-engineered clinical processes designed toreduce waste. In further embodiments of the invention, means forreal-time tracking of the identity of a drug in a syringe and itsconcentration as well as the amount delivered to a patient are provided.Such a tracking function of the invention can flag drugscontra-indicated for the patient when the system is coupled to acomputerized medical record that includes the patient's history andphysical examination.

The present invention also provides asset tracking and efficientinventory control via a system for tracking and instantly locatingmobile capital equipment in a hospital or other setting as well as formonitoring which medical supplies in an inventory and components orsupplies are expired or will soon expire. Further a system is providedthat facilitates the localization and removal of products recalled bytheir manufacturers or a regulatory agency.

The present invention also provides a system that can quickly verifywhether there are foreign objects left in a surgical cavity without theneed for X-ray radiation.

The various information tracking and identification functions describedabove are made possible by a means of marking medical devices, systemcomponents, disposables, consumables, or other products with anindicator or “smart” tag. The invention provides one such indicator tagin the form of a radio frequency identification (“RFID”) tag which canbe affixed to an article thereby labeling it with certain informationthat can be read by a nearby reader. An RFID tag may be written to inorder to store additional or updated information or it may be employedas a simple use indicator whereby the tag is altered upon its associatedarticle being used in a way that the reader can detect. The inventionalso provides means for shielding the RFID tags from unintended radiofrequencies. Several advantages of RFID tags exist, but the presentinvention also provides alternative means for marking devices for theabove functions. One other such device is an electrical EEPROM tag whichcan store much information about the article to which it is attached.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a drawing of a radio frequency identification (“RFID”) tagcombined with a breakable conductive loop;

FIG. 2 is a perspective drawing of an RFID tag with a breakableconductive loop that is used as a label on a vial;

FIG. 3 is a side view of an RFID tag used as a label on a syringetogether with at least one linear array of Hall effect sensors;

FIG. 4 is a perspective view of a box housing a medical kit or supply orcomponent that is tagged with an RFID label that has a peel away cover;

FIG. 5 is a partially-exploded view of an Electrically ErasableProgrammable Read Only Memory (EEPROM) tag showing electrical contactbetween an EEPROM tag embedded in a removable supply or component and anEEPROM reader/writer attached to a capital equipment unit;

FIG. 6 is a view of a suitable connector on a capital equipment unit foruse with EEPROM tagged supplies, components and disposables;

FIG. 7 is a view of a suitable connector on a disposable supply orcomponent for use with EEPROM tagged supplies, components anddisposables; and

FIG. 8 is a view of a medical device incorporating an RFID reader/writerthat interfaces with at least one of an array of RFID tags and sealsattached to medical supplies, components, accessories and peripheralequipment.

DETAILED DESCRIPTION OF THE INVENTION

A recognition sub-system of a medical device system reads andauthenticates the identification and/or source of a drug, supply,component or attachment that is associated with a medical device system.Such a medical device system could be a sedation and analgesia deliverysystem such as that disclosed in U.S. patent application Ser. No.09/324,759 filed Jun. 3, 1999, the entirety of which is hereinincorporated by reference. The sedation and analgesia system ofapplication Ser. No. 09/324,759 includes a patient health monitor deviceadapted so as to be coupled to a patient and generate a signalreflecting at least one physiological condition of the patient, a drugdelivery controller supplying one or more drugs to the patient, a memorydevice storing a safety data set reflecting safe and undesirableparameters of at least one monitored patient physiological condition,and an electronic controller interconnected between the patient healthmonitor, the drug delivery controller, and the memory device storing thesafety data set; wherein said electronic controller receives saidsignals and in response manages the application of the drugs in accordwith the safety data set. The recognition subsystem of the presentinvention may be used with such a sedation and analgesia system tofurther manage the application of the drugs in accord with theidentification, source or other information regarding a drug, supply,component or attachment to the sedation and analgesia system. The safetydata set, as referred to by the electronic controller, may furtherinclude data regarding proper values for the identification and/orsources of such drugs, supplies, components or attachments.

The medical device system associated with the recognition subsystem ofthe present invention could also be any of numerous other systems thatemploy drug or other consumable or disposable supplies and components.Examples of other systems with which the recognition subsystem of thepresent invention could be associated, include, among others, anesthesiasystems (e.g., induction machines, anesthesia machines andworkstations), imaging systems (e.g., X-ray, MRI, CAT) systems, therapysystems (e.g., radiation and chemo-therapy machines), treatment systems(e.g., dialysis machines), interventional systems (e.g., heart/lungbypass machines, cell savers), and diagnostic systems (e.g.,colonoscopes, mammographs).

The present invention provides a means that, if a non-certified orpreviously used drug, component or supply is attached to an associatedmedical device system, will prevent a medical device system frominitiating the function, or functions, that it is designed to provide.For example, with a sedation and analgesia system, the administration ofsedative or analgesic drugs would be prevented in order to ensure thereliability of performance of the system.

Regarding the exemplary medical device system of U.S. patent applicationSer. No. 09/324,759, examples of function-critical drug containers, therecognition of which would be performed according to the presentinvention, include those containing Propofol, remifentanil,dexmedetomidine, or intravenous xenon (xenon dissolved in a lipidemulsion). Similarly, examples of function-critical supplies andcomponents that might be connected to, and used with the noted sedationand analgesia system include a respiratory monitor, oxygen deliverytubing, a drug infusion cassette, drug infusion tubing, a one-wayanti-reflux valve, a patient audio earpiece to provide audible promptsfor testing or monitoring, and a resuscitation kit.

Function-critical drug containers, supplies, and components arerecognized, according to the present invention, by way of a data carrieror “tag” that is associated with them and then read by a reader device.A data carrier is preferably generic in the sense that data is notrepresented by physical characteristics of a tag (such as itsfundamental resonant frequency). The data carrier may also simplyindicate the status of an article as used or unused. A data carrier or“tag” may be small (e.g., 3 mm square) and can store relatively largeamounts of data. Selected tags preferably have a lifetime that is equalto or greater than the shelf life of products being tagged.Additionally, selected tags may provide data encoding that is genericand not specific to attributes (e.g. physical dimensions or resonantfrequency) of a tag. Further, data storage capacity of a tag preferablyis sufficient to allow creation of a unique ID number for eachindividual medical supply or component. An example of a tag that thatmay be used with the present invention is a radio frequencyidentification (“RFID”) tag. Other suitable electronic taggingtechnologies include programmable memories like EPROMS, EEPROMS andmagnetic strips.

FIG. 1 shows an RFID tag 10 attached to a thin backing 14 that is madeof a material, such as a self-adhesive paper, that can be torn by hand.RFID tag 10 consists of a miniature integrated circuit 19 and an antenna12. A conductive loop 16, that can be implemented with, among otherthings, conductive ink or fine breakable conducting wire such as copper,is deposited on the backing 14 and is in electrical connection to theintegrated circuit 19 via conductive traces and pads 18. The conductivepads 18 also provide physical separation so that the conductive loop 16can be deposited or connected using conductive glue with coarseresolution on the RFID tag 10. In embodiments where the conductive loopis breakable, when the breakable loop is broken, such as when the thinbacking membrane 14 is torn, data in the RFID tag is mechanicallyreprogrammed.

In a particular embodiment, the invention utilizes a passive,inexpensive, disposable, non-contact, non-volatile read/write radiofrequency identification (“RFID”) tag to authenticate a medical supplyor component and indicate its use status (such as, used, unused, pastexpiration or inspection date, number of times used) for single-use andmultiple-use medical supplies. The reading/writing zones of areader/writer are advantageously located to encompass the tags of taggedmedical supplies when used in conjunction with a capital equipment unitoperably coupled to the reader/writer. The RFID reader/writer isattached to or associated with the medical device system andcommunicates with a CPU of the system. Software resident on the CPU ofthe system in turn may interface and communicate with other systems likea local area network (LAN), inventory control system, automated chargecapture and billing system, medical record system, as well as theInternet and the Web and other Internet- and Web-based applications.Data concerning a smart medical supply or component may also be used byother subsystems of a capital equipment unit, for example, to facilitateand speed a semi-automated pre-use or functional check of the capitalequipment unit. A reader/writer could interface to an RFID tag via,among other techniques, inductive coupling (e.g., by using an antenna)or capacitive coupling (e.g., by using conductive carbon ink that picksup electrostatic charges from reader). RFID tags from manufacturers likeTI, Motorola, Philips, Mitsubishi, Intermec, Micron and SCS may be usedwith this invention.

In particular embodiments of the present invention, the amount of datathat can be stored in a tag is large enough such that each single taggeditem has a unique, individual identification number as well as a batchnumber. The batch number may form part of the unique identificationnumber or may be separate therefrom. Having enough data storagecapability on a tag to assign a unique number to each individual taggedmedical supply and component as it makes its way from a manufacturer toa patient enables the creation of powerful databases providing real-timedata to improve the efficiency of manufacturing, distribution,warehousing, restocking of medical supplies and components, andreduction of waste.

As an added safety measure in the event of a product recall, the batchnumbers and unique identification numbers of recalled products may beprogrammed into associated medical device systems, such as sedation andanalgesia delivery systems or dialysis machines (among others), or atany dispensing locations such as pharmacies, stock rooms and cleanrooms. Thus, any tainted drug vial, dialysis cartridge, recalled medicalsupply or component, or the like, slipping through a recall could beautomatically identified and rejected from use upon the system'smatching a list of unique identification numbers or batch numbers ofrecalled products. The list of unique identification numbers and/orbatch numbers of the recalled products could be downloaded from theInternet or Web to the medical device system to provide worldwide,quasi-instantaneous and timely dissemination of specific informationregarding recalled products, as the information is being updated at amanufacturer's or regulatory agency's web site. The tag may also includeamong its stored data an address such as a Universal Resource Locator(URL) where updated information about a tagged product such as recallstatus and newly discovered data such as contra-indications (not to beused with certain drugs, patients, environments or conditions).

The invention also provides a reader/writer on a medical capitalequipment unit that selectively reads, or reads and writes to, any giventag among a plurality of tags associated with different disposable andreusable medical supplies and components used in conjunction orassociated with the capital equipment unit. The invention alsocontemplates using more than one reader/writer with a medical capitalequipment unit, such as in situations where a single reader/writerembodiment, although cheaper and easier to implement, may not provideenough area coverage or redundancy in applications where at least one ofthe functions selected from the group of reading and writing iscritical. In further embodiments, spare medical supplies and componentscan be stored in close proximity to, or inside a capital equipment unit,without risk that they are unintentionally written to as “used” whenthey are actually unused spares.

In particular embodiments of this invention, the recognition subsystemis able to “write” to a medical supply or component that it has beencontaminated through use and is no longer suitable for use on subsequentpatients. These tagged items may also be packaged along with othersupplies in a kit. The kit has integrated into it the ability to berecognized and “read” by the system as quality certified and used orunused and “written to”, once used by the system, labeling it as acontaminated article. This reading and writing function may beaccomplished in numerous ways as herein described.

For articles susceptible to contamination that are designed for multipleuses, it is possible to provide a “rewrite” function, to enable articlesto be re-labeled as suitable for use once they have been properlycleaned and quality certified for re-use. Further, it is possible forthe write function to store information regarding the number of cyclesof use that an article has experienced and to compare this informationto a certified life cycle of uses recommended. This writing function maybe accomplished through numerous means described later.

Further features of the read/write system of the present invention mayinclude the read/write device not requiring line of sight, physicalcontact or close proximity, relative movement or scanning, and allowingsimultaneous reading of multiple tags and writing or rewriting to aspecific tag in the presence of other tags. More specifically, RFIDtags, according to the present invention, are autoclavable and resistdirt, grease, scratches, and wear and tear. More than one RFID tag canbe read from or written to at the same time. RFID readers do not requireline of sight reading nor direct contact with or relative movement tothe tags. RFID readers can read at distances exceeding 4 feet dependingon antenna size and power.

In particular embodiments of the present invention, RFID tag 10 is asmall (e.g., 1.8″×1.8″), thin (e.g., 0.015″ maximum/0.003″ minimum),self-adhesive label such as the inductively-coupled Tag-it RFID labelfrom Texas Instruments which features 256 user programmable data bits at4 feet read range and at 13.56 MHz. Such tags can be substituted for aregular label on a vial (e.g., a vial of Propofol or other drug or anyother medical fluid) or other disposable or reusable medical supply orcomponent. As will be appreciated by one skilled in the art, 256 bitscan generate 1.2×10⁷⁷ (i.e., 2²⁵⁶) unique ID numbers.

As depicted in FIG. 2, a breakable conductive loop 20 is coated orplaced over a drug or medical fluid vial 22 including a pull-tab overthe vial stopper. The breakable conductive loop is affixed, for example,using conductive glue, to an RFID tag 24 that is attached to the vial. Aconventional label 26 that indicates the contents of the vial isoptionally placed over the RFID tag to conceal it. When the pull-tab isremoved from vial 22, such as when the user is ready to swab the stopperwith alcohol and spike it, the conductive loop is broken. The removal ofthe pull-tab indicates to an RFID reader/writer that is associated withthe medical device with which the vial 22 is used that the vial with thebroken conductive loop 20 is the one that is being used and thus is theone that should be written to as used. If spare, unused or unopenedvials are also present within the reading/writing range of the RFIDreader/writer, they are not written to as used.

A further aspect of the present invention uses a tearable or breakableconductive loop made of conductive ink or material or fine breakablewire made of conductive material like copper to indicate the use statusof a product, kit or wrapper. For example, if the loop is intact, a bitin a tag corresponding to the use status will be set to 1. However, oncethe loop is broken (such as after a package has been opened or a sealbroken), the use status bit will be set to 0. The breakable conductiveloop could be used, for example, to indicate whether an emergencyresuscitation kit has been used since it was last restocked orfunctionally tested and certified, replacing a mechanical seal currentlyused for the same function. The breakable conductive loop could also beused for pre-assembled kits. A breakable conductive loop may be placedaround a glued edge of a kit package. When the kit is opened, some ofthe conductive ink or conducting material forming a breakable conductiveloop will adhere to the glue and the conductive loop will be broken.

For cost-sensitive applications of the present invention, a read-onlytag could be used with the breakable conductive loop. Thus a data bitwhose status is determined by the integrity of the conductive loop,representing for example the use status of a product, would bemechanically “programmed”, providing a limited “write-once”functionality. Setting a data bit to either 1 or 0 according to theintegrity of a conductive loop will be obvious to one skilled in theart. For example, a data bit could store a voltage between 3.5 and 5 Vto represent 1 and a voltage between 0 and 1.5 V to represent 0. Byconnecting a pin connector controlling the state of the data bit to +5Vvia a conductive loop, the data bit is pulled high (encoding a 1)whereas the same data bit is pulled low (encoding a 0) if the loop isbroken.

Alternatively, an RFID label with a conductive breakable loop may beplaced on a medical supply or component such that the conductive loophas to be broken before the medical supply or component is used. Forexample, the label or conductive loop could be placed on top of astopper or pull-tab in a propofol or other drug or medical fluid vial.Thus, a reader will be able to determine which one of the propofol orother drug vials or medical fluid vials are actually in use and whichcorresponding concentration to use for dosage calculations and targetcontrol infusion. Alternatively, short-range RFID tags can be used forthis application.

The status (intact or broken) of the breakable conductive loop can beused to infer the use and/or the sterility status (e.g., unused andsterile or used and unclean) of the medical or non-medical item that istagged with a read/write or read-only RFID tag. For example, a brokenconductive loop generally indicates use or loss of sterility of aformerly airtight package containing sterile products. A brokenconductive loop may not always imply use of its associated tagged item.For example, a vial that has not yet been spiked is not yet used even ifthe pull-tab has been broken. Still, even with this example, theconductive loop being broken still may indicate which vial among amultitude of vials within reading and/or writing range of an RFID readerand/or writer is to be used.

This vial identification concept of the invention can also beimplemented with a regular RFID label without a breakable conductiveloop, an example being the Tag-It from Texas Instruments. When suchregular RFID labels are used, the unused or spare vials withinreading/writing range of an RFID antenna may be shielded from theantenna by placing them in a metallic enclosure, such as a metallicdrawer, or by placing them in metallized plastic wrappers.Alternatively, RFID antennas with very short range may be used,especially in applications where the RFID antenna's reading and/orwriting range does not have to be large, for example, to cover multipletagged items.

Those skilled in the art will readily appreciate that the utility of theRFID tag embodiments herein disclosed is independent of whether the taghas a breakable conductive loop 44 connected to it. Various ways toprotect electronically writable RFID-tagged items from beingunintentionally overwritten and identified as used exist, includingshielding them in a metallized plastic wrapper. Radio waves cannotpenetrate a metallic enclosure and the metallized plastic wrapper mayachieve the same functionality. Medical supplies and components may beplaced in the metallized plastic wrappers during production to keep themclean or sterile while also shielding them from radio waves.

As seen in FIGS. 1 and 2, self-adhesive RFID labels typically arereadily accessible and may therefore be tampered with. For example, anoriginal RFID label on a used medical supply or component might beremoved and replaced by an unauthorized RFID label that falselyidentifies that a medical supply or component is “unused.” To maketampering and/or unsafe reuse harder, the present invention contemplatessoftware of a capital equipment unit that stores the individual ID foreach medical supply or component used with it as a means to verifywhether the ID of a medical supply or component was copied and used morethan once with that particular capital equipment unit. The presentinvention also contemplates networking machines or capital equipmentunits to a central databank so that if a copied ID is used on a secondmachine or capital equipment unit in the network, it can still beidentified as being used. As an additional anti-tampering feature,individual identification numbers for each medical supply or componentare encrypted and the corresponding decryption algorithm is resident oncapital equipment units or a server accessed through the Internet orWeb. Tampering is also discouraged by imbedding the RFID tag within amedical supply or component during manufacture, to make it inaccessibleor whereby physical access to the imbedded tag would disable the medicalsupply, e.g., by creating a leak in an otherwise airtight system.

FIG. 3 depicts a label 36 (the label comprising an RFID tag) identifyingthe contents of a syringe 28 (where the syringe is an example of an itemthat may be tagged according to the present invention). To identify theidentity and concentration of drugs manually administered via syringe, aread-write or read-only RFID tag may be incorporated into self-adhesive,color-coded labels currently used to identify drugs in differentsyringes. The color-coded labels are affixed to each syringe immediatelyafter drawing each drug, per current clinical practice. The RFID tag hasencoded thereon data such as drug identity, concentration, syringe size,a unique ID or batch number, as well as use status of the taggedsyringe. Linear movement of a syringe plunger is tracked by placingmagnetic ink or material on a perimeter of a proximal end of theplunger. A linear array or arrays of Hall-effect sensors, physicallyspaced or staggered to provide appropriate resolution of volumemeasurement picks up residual magnetic fields from the magnetic ink ormaterial, thus tracking linear movement of the syringe plunger and thusvolume of the syringe content administered if the cross-sectional areaof the syringe barrel is known. The RFID tag may contain, among otherdata, the identity of a drug, its concentration, and whether the syringeattached to the tag has previously been used on another patient. In suchembodiments in which a syringe is tagged, magnetic ink or material maybe deposited or placed along the circumference of plunger handle 30 of asyringe 28, i.e., around where the user's thumb is usually placed. Atleast one linear array of Hall effect sensors 32 may be employed totrack the linear movement of the plunger 30 when a drug is manuallyadministered by the user. Guides 34 position and support the syringesuch that the plunger handle 30 is in proximity to the array or arraysof Hall effect sensors and in doing so, determine the size of thesyringe, so that its cross-sectional area may be determined. More thanone linear array of Hall effect sensors may be used if the sensordimension exceeds a desired spatial tracking resolution. In such asituation, the sensors may be staggered along multiple linear arrays inclose proximity to the circumference of the plunger handle 30 so as toprovide the desired spatial tracking resolution.

Another embodiment of the present invention includes an RFID tag with abreakable conductive loop attached as an RFID seal to a container thathouses a non-medical or medical kit, a supply of components (such as aresuscitation kit for conscious sedation or anesthesia), or a sterile,clean, tested, and certified component of some non-medical or medicalequipment. The RFID seal may store the date of inspection, cleaning orcertification of the contents inside the container to which the seal isattached. Other data that may be stored in such a seal includes, but isnot limited to, the names of the personnel performing a procedure, thecleaning, and the certification and the due dates for the next scheduledprocedure, where applicable.

FIG. 4 depicts a medical kit containing, for example, medical suppliesand/or components necessary for a particular procedure or surgery. Thekit has a peel-away cover 40. The peel-away cover has an RFID tag 42attached to it. The RFID tag could be in the form of a label (as shown)or in a non-label format. When cover 40 is peeled away prior to aprocedure, breakable conductive loop 44 is broken indicating to a RFIDreader and/or writer which kit has been opened and should be written toas being used. This is especially important if, in clinical use, morethan one RFID-tagged medical kit, component or supply may be presentwithin the read/write range of the RFID reader/writer of a medicaldevice system. The conductive trace could also be laid out on theinternal surface of peel-away cover 40 such that if cover 40 is cut,instead of peeled away, the conductive trace is broken.

The present invention provides for the elimination of the daily checkingof back-up equipment for an associated capital equipment unit, (suchequipment may include resuscitation kits, all appropriate emergencymedical devices, kits of components, the components and supplies, suchas, among others, self-inflating resuscitation bags, emesis aspirators,laryngoscopes, endrotracheal tubes, and drugs) are placed in a containerthat is sealed with a read/write or read-only RFID tag with a breakableconductive loop. The container could be a wheeled cart with drawers or amedical suitcase, among other forms. As long as the RFID seal (abreakable conductive loop) remains intact and the sealed container'scontents are not past their due date for inspection (as may be gleanedfrom the encoded RFID tag), users can have a high level of confidencethat all necessary medical supplies and devices required to manage anemergency are present and functioning. The RFID tag on a back-upequipment container may be in the form of a label that includes atearable or breakable conductive loop that is torn or broken when thecontainer is opened. The RFID label may optionally be self-adhesive.Before use, a container housing a back-up emergency kit is placed withinthe reading zone of its associated capital equipment unit so that theRFID seal can be read. The RFID tag may contains the due date or duedates for the next inspection or inspections of the back-up equipment aswell as the date of the last inspection and names of personnelperforming the last inspection or inspections. Thus, a capital equipmentunit when used in conjunction with the tagging according to the presentinvention can automatically inform a user or clinical engineering staffwhen a kit is past its due date for re-inspection and re-stocking.

In further embodiments that encompass a semi-automated pre-use check ofa capital equipment unit and its components, the status of an RFID sealor tag is automatically read. If the seal is broken, indicating the kitmay have been used and items may be missing, the user may be warned ofsuch during the semi-automated pre-use check via a user interfacesystem. The pre-use check process may also utilize the taggedinformation to verify that all required supplies and components arepresent, unused (if prior use would be a detriment), and not past theirexpiration dates. The concept of a seal comprising a tag with abreakable conductive element according to the present invention isapplicable to any field where it is critical that rarely used equipmentbe guaranteed as ready and functional when it is eventually needed.Applicable fields, here, could include but are not limited to firefighting, rescue, emergency response, and the military.

As described above, a passive read/write RFID (or a suitable alternativeelectronic and/or optical technology) tag may be affixed to asingle-patient-use (e.g., a vial of Propofol or other drug or medicalfluid vials or gas delivery circuits) or multiple-patient-use (e.g., amonitoring harness) medical supply or component intended to be used witha particular piece of capital equipment (e.g., anesthesia machines orworkstations, dialysis machines, sedation and analgesia deliverysystems, or X-ray machines) having the ability to read from and write tothe RFID tag or other suitable alternative electronic and/or opticaltechnology. A reader/writer on the capital equipment unit is locatedsuch that all tags attached to associated supplies and components willbe within reading/writing range of the reader/writer device when thetagged medical supplies and components are used in conjunction with thecapital equipment unit. Preferably, but not necessarily, thereader/writer is located on the capital equipment unit (such as amongothers anesthesia machines, sedation and analgesia machines, dialysismachines, X-ray machines) with which a medical supply or component isemployed and is interfaced to at least one or more CPU controllingoperation of the capital equipment unit. Alternatively, thereader/writer could be tethered (or in wireless communication) to thecapital equipment unit but outside it to provide best coverage of tags,or incorporated within a hand-held device such as a personal digitalassistant. For purposes of example only, one of the data bits isassigned to represent a used/unused status of a disposable medicalsupply or component as 0/1 respectively. If the reader reads that themedical supply or component has been previously used (0), then a usercan be warned about the danger of cross-contamination and prevented fromusing a previously used medical item.

A further function of the RFID tags of the present invention is theverification that sponges or surgical instruments have not beeninadvertently left in a surgical cavity in a manner that does not incurthe undesirable time expenditure or radiation exposure involved withtaking a radiograph of the surgical cavity. Surgical instruments andsupplies may be tagged with a disposable RFID tag. Scanning a hand-heldRFID wand or reader over a surgical cavity will allow detection of anytagged objects left behind. This scanning can be done before thesurgical cavity is closed.

Electronic tags may also be used to indicate use and store informationabout the items to which they are connected. Examples of items that maybe tagged with an electronic tag include but are not limited todisposable medical supplies or components, such as an O₂ cannula, apropofol vial, an infusion drug pump cassette, a set of infusion tubing,a resuscitation kit, a set of ECG pads, and an earpiece adapted for useby a patient, intended for use with any of the sedation and analgesiadelivery system disclosed in U.S. patent application Ser. No.09/324,759, anesthesia machines, anesthesia workstations, dentalmachines, veterinary anesthesia machines, dialysis machines, X-raymachines that employ drugs, or other systems that use reusable,consumable or disposable supplies and components. Similarly, electronictags according to the present invention can be used for authenticationand identification of any drug, supply, component or attachment that isattached to a medical device system for use therewith.

FIG. 5 depicts how an Electrically Erasable Programmable Read OnlyMemory (EEPROM) integrated circuit (“IC”) 60, (e.g., Microchip 24C00)can be embedded into a plastic molding at a machine-interfacing end of adisposable medical supply or other component 62. Circular metallic pads58 (only one set of which is shown in the figure for clarity) provideelectrical connection to pins on the EEPROM. Five circular pads may beused for the following functions: serial clock, serial data, power,ground and detect (used to detect when the EEPROM is plugged in) butmore or fewer pads could also be used to implement the electronictagging concept of the present invention. Circular pads 58 makeelectrical contact with electrical contacts 52 (e.g., Pogo connectors),which may be spring-loaded and which are housed in connector 50 that iselectrically connected to EEPROM reader/writer 53. EEPROM reader/writer53 may be based on, for example, a Motorola HC12 microcontroller.According to particular embodiments of the present invention, an EEPROMintegrated circuit (such as a Microchip 24C00) is embedded into adisposable or re-usable medical supply or component. Data encoded intothe EEPROM is read by a microcontroller, such as a Motorola HC12microcontroller. The microcontroller may also write to the EEPROM. Thecircular pads are protected inside a cavity formed in male connector 56.Male connector 56 mates to female connector 54 and in doing so providesboth indexing and electrical contact between the medical supply orcomponent and the medical capital equipment unit. The purpose ofindexing (or keying) is to prevent the medical supply or component frombeing attached to its associated capital equipment unit or device in anincompatible way or orientation. FIGS. 6 and 7 depict end-on views ofthe connectors. Those skilled in the art would also appreciate thatconnectors ensuring electrical contact between an EEPROM and an EEPROMreader/writer can have various other configurations not shown in thesefigures.

Repeated connection and disconnection of disposable or re-usablesupplies and components to the capital equipment may cause theconnectors on the capital equipment unit side to wear out thus resultingin poor or intermittent contact. To compensate for this problem, thepresent invention provides in some embodiments, an electrical connectionof the EEPROM tag to the reader/writer unit through a POGO connector,for example, that exerts a mechanical force on the connectors 54 and 56to ensure good electrical contact. The more costly part of the POGOconnector may be placed on the capital equipment side while the lesscostly part of the POGO connector may be placed on the disposable orre-usable components. Alternatively, the present invention may provide a“middleman” connector between the capital equipment and its associatedtagged components. Such a middleman connector may be replaced atperiodic intervals or after a particular number of uses, beforesignificant wear occurs.

EEPROM chips may be written to as “used” thus allowing for theprevention of re-use of and thus possible cross-contamination of thesupplies or components that are tagged. Alternatively, read only orread/write EEPROMS can also be used to implement tamper-evident sealswhen combined with a breakable conductive loop.

A write-once EEPROM chip may be used as an electronic tag according tothe present invention whereby once one is written to as used it can nolonger be identified in any other way. A write-once EEPROM used with amedical supply cannot be rewritten to as being “unused” in situationswhere it has indeed already been used even if an encryption code andinstructions for writing to the EEPROM are available. Thus, write-oncechips may provide a means for preventing used supplies from beingre-used.

EEPROM tags may also provide other functions for the safe and efficientuse of the items they are used to tag. When EEPROM tags that can storesufficient bits, e.g. 128, are used as the tags according to the presentinvention, each individual medical supply or component having such tagscan be assigned a unique ID number and/or encryption code. Such uniqueidentifiers on an EEPROM tag may be used to indicate that a medicalsupply or component is from a quality, certified, safe, and trustedsource, thus providing an authorization function. Authentication mayalso be made from such information as whether the tagged medicalsupplies or components have been tested to be compatible with theirassociated capital equipment unit, whether the tagged medical suppliesor components have been recalled or prohibited from use by regulatoryagencies, and whether the source of the supplies or components is legal,i.e., licensed to manufacture or supply the supplies or components.EEPROM tags may also facilitate semi-automation of pre-use checks ofmedical equipment, charge capture and prevention of use of recalledmedical supplies and components once the EEPROM tags are in electricalconnection with a reader/writer in a capital equipment unit.

Alternatively, magnetic strips like those at the back of credit cardscan be used as read/write tags for medical supplies. In such embodimentsof the present invention, a read head is implemented to contact themagnetic strip when the strip is moved past the read head. This movementdoes not need to be constant but cannot be zero. This movement may beobtained when the read head is positioned on a capital equipment unitsuch that during the physical installation of a tagged medical supply orcomponent with that unit, the tag contacts the read head and movesrelative to it. Similarly, upon removal of the medical supply orcomponent from the capital equipment unit after its use, the magneticstrip may also contact a read/write head so that its encoded data isaltered or its serial number is logged to indicate that the particularmedical supply or component has been used.

Other use-indicating mechanisms may be employed according to the presentinvention. For example, physical indicators such as thermochromatic inkthat changes color on heating or “scratch-and-sniff” coatings may beused in certain situations and on certain items to be tagged. Further,alternative electronic data transfer mechanisms, such as Bluetooth forexample, could be used in tagging systems and methods of the presentinvention.

FIG. 8 depicts an example of a medical device or capital equipment unit70 that incorporates an RFID reader/writer 72 to interface with variousRFID-tagged medical supplies or components according to the presentinvention. A housed antenna 74 may be connected to an RFID reader/writer72. Antenna 74 communicates to RFID tags 24, 82, 90 and 96. Inembodiments of a medical device or capital equipment unit 70 used withthe present invention in which the RFID tags will be located outside thereading/writing range of housed antenna 74, a larger antenna 76 may beimplemented by placing a loop of conductive material, such as metal andconductive paint, inside a chassis or frame of the medical device orcapital equipment unit. A larger antenna placed in the chassis ofmedical device 70 has more reading/writing range than the housedantenna. Reader/writer 72 is interfaced to at least one CPU of thecapital equipment unit 70, and that CPU can optionally be interfacedwith external processing or data sources such as among others a LAN, aWAN, the Internet, and the Web.

If spare medical supplies (e.g., 2 spare propofol vials of differentconcentrations, in addition to one being used) are present within areading/writing zone, a reader/writer on a capital equipment unit willdetect 3 propofol vials but may not know which concentration to use forpropofol delivery calculations or which propofol vial should be writtento as “used”. In such situations, spare medical supplies stored withinthe reading/writing range of a reader/writer operably coupled to acapital equipment unit can be placed in a metal enclosure where they areshielded from RF waves.

The concern with RFID-tagged disposable medical supplies and componentspossibly being unintentionally written to as used may be solved byplacing spare medical supplies and components in metallic enclosures,like metallic drawer 98 shown in FIG. 8 to shield the spare RFID-taggedmedical supplies and components from the RFID reader/writer.

FIG. 8 also depicts a resuscitation kit 94, as described above, adaptedto contain items required for managing an emergency during the use ofthe medical device or capital equipment unit 70. RFID tag 96 with abreakable conductive loop acts as a seal. The conductive loop is brokenwhen resuscitation kit 94 is opened. A vial 22 for holding medical fluidor a drug such as Propofol is shown tagged with an RFID label 24. Thevial is spiked onto a drug cassette 88 that is tagged with an RFID label90. The disposable or reusable drug cassette snaps onto a peristalticpump mechanism (not shown) attached to the medical device or capitalequipment unit. The peristaltic pump delivers the Propofol or othercontent of the vial to a patient via intravenous line 92. Disposable orreusable O₂ cannula hose 80 is connected to unit 70 and is tagged withan RFID tag 82. All RFID tags and labels are shown placed withinreading/writing range of the RFID reader/writer 72.

1. An electronic tag for storing and providing information regarding a tagged object, comprising an electronically readable data transmitter coupled to a breakable conductive element, said data transmitter being adapted to transmit previously stored data regarding said tagged object, and said breakable conductive loop causes a first signal to be transmitted with said previously stored data when said breakable conductive material is intact and a second signal to be transmitted with said previously stored data after said breakable conductive material is broken.
 2. The electronic tag according to claim 1, wherein said breakable conductive element is formed from conductive material on a breakable seal.
 3. The electronic tag according to claim 2, wherein said first signal represents that said tagged object is unused and said second signal represents that said tagged object has been used.
 4. The electronic tag according to claim 2, wherein said first signal represents that a package of said tagged object is sealed and said second signal represents that a package of said tagged object has been opened.
 5. The electronic tag according to claim 1, wherein said electronically readable data transmitter comprises a radio frequency identification tag.
 6. The electronic tag according to claim 1, wherein said electronically readable data transmitter comprises an EEPROM.
 7. The electronic tag according to claim 1, wherein said electronically readable data transmitter comprises a readable magnetic strip.
 8. The electronic tag according to claim 7, wherein said medical supply or component kit is for use with a sedation and analgesia system.
 9. The electronic tag according to claim 8, wherein said electronic data transmitter comprises a read/write memory such that said previously stored data can be altered and said tearable label is adapted to serve as a tamper-evident seal and electronic inventory of an item selected from the group consisting of a medical apparatus, medical equipment storage device, resuscitation kit, medical kit, sedation and analgesia kit, sedation and analgesia resuscitation kit, drug or equipment container, and a drug or equipment package.
 10. The electronic tag according to claim 1, wherein said electronic data transmitter comprises a read/write memory such that said previously stored data can be altered by a user of a product attached to said tag or by a reader/writer device.
 11. The electronic tag according to claim 1, wherein said electronic data transmitter comprises a read-only memory such that said previously stored data cannot be altered by a user of said tag or by a reader/writer device.
 12. An electronically tagged medical supply or component, said supply or component comprising at least one of a mechanical use indicator and a generic electronic data carrier tag, said tag having a first data set that represents information regarding said medical supply or component, and said tag further having a second data set having values dependent upon the physical status of said mechanical use indicator, wherein said first data set and said second data are readable by an electronic data reader or reader/writer.
 13. The medical supply or component according to claim 12, wherein said tag is attached to packaging of said medical supply or component and utilizes a data carrier mechanism selected from the group consisting of a radio frequency identification, EEPROM, and magnetic strips.
 14. The medical supply or component according to claim 12, wherein said electronic data reader utilizes said first and second data sets to determine according to a predetermined set of rules how a system connected to said reader or reader/writer utilizes said medical supply or component.
 15. The medical supply or component according to claim 12, wherein said first data set is read-only.
 16. The medical supply or component according to claim 15, wherein said read-only data set represents information regarding at least an identification of said disposable medical supply or component to a medical care system connected to said electronic data reader.
 17. The medical supply or component according to claim 12, wherein said tag is a radio frequency identification tag and is inductively coupled to said electronic data reader.
 18. The medical supply or component according to claim 12, wherein said tag is a radio frequency identification tag and is capacitively coupled to said electronic data reader.
 19. The medical supply or component according to claim 12, wherein said first data set can be electronically written to by said electronic data reader/writer to record a change in a status of said medical supply or component.
 20. The medical supply or component according to claim 19, wherein said change in status relates to the status of said medical supply or component as used or unused.
 21. The medical supply or component according to claim 19, wherein said change in status relates to the use status of said medical supply or component as the number of uses of the supply or component.
 22. The medical supply or component according to claim 19, wherein said change in status relates to the use status of said medical supply or component as the expiration date of the supply or component.
 23. The medical supply or component according to claim 12, wherein said mechanical use indicator comprises a breakable conductive loop connected to said tag wherein said loop assigns said second data set a first value when intact and a second value when broken.
 24. The medical supply or component according to claim 23, wherein said breakable conductive loop comprises conductive material applied on a breakable seal wherein said breaking of said seal to use said medical supply or component causes said conductive loop to be broken.
 25. The medical supply or component according to claim 23, wherein said first data set is read-only. 